The present invention relates to an amplifier and method to amplify current. More specifically, but without limitation, the present invention relates to a drift tube amplifier and method to amplify current that can be used in conjunction with a chemical agent detection system.
Amplifiers are, but without limitation, mechanisms or devices that make certain outputs greater or larger. Specifically, amplifiers may increase the amplitude of something or allow it to be heard or detected easier. The United States Navy utilizes amplifiers in chemical agent detection systems, specifically systems that detect nerve and blister agents. These amplifiers must amplify extremely low currents that are produced when ions strike a Faraday Cup. A Faraday Cup may be defined, but without limitation, as a device for precisely measuring the current carried by a beam of particles.
The United States Navy utilizes Ion Mobility Spectrometry (“IMS”) to identify different species of chemical agents, including nerve and blister agents. IMS is a gas-phase ion separation technique. Ions are formed in a source region, accelerated through a potential gradient with a counter-current drift gas (typically air), and the ions collide with a collector (typically a Faraday Cup). When an ion collides with the collector (the Faraday Cup), it induces an extremely small current. The current must be converted and then analyzed by a processor or processor board. The processor board, based on the current, determines if there is a chemical agent in the air. Since the current is extremely small, it must be amplified and transformed in order for the processor board to properly read and analyze any input received. Thus, there is a need for an amplifier that can transform and amplify the current into a form such that the current may be read and analyzed.